Router technology Basics

China's vro technology is developing rapidly, and technological standards are also being innovated. So I have studied the basic knowledge and principles of vro technology. I would like to share it with you here and hope it will be useful to you. Due to the continuous advancement of social informatization, people's demand for data communication is increasing.

Since the launch of TCP/IP protocol clusters in the middle of 1970s, it has become a factual standard for network layer communication protocols. TCP/IP-based interconnected networks have become the largest and most important networks. As the core device of an IP network, routers have been widely used. As the core equipment of the IP network, router technology has become a key technology in the current information industry, and its equipment plays an increasingly important role in data communication. At the same time, due to the powerful features and complex technology of the router technology equipment, manufacturers have too many choices for the realization of the router technology. As the core device of the public network, vro technology must follow the equipment specifications to propose the minimum requirements. Therefore, it is important and necessary to standardize router devices. The standard about the router equipment has been published as follows: YD/T1156-2001 "router Test Specification-high-end router"; YD/T1098-2001 "router Test Specification-low-end router".

Vro technical definition

Router technology is a packet forwarding device that works at the network layer of the OSI reference model. Vro technology implements network interconnection by forwarding data packets. Although routers support multiple protocols, such as TCP/IP, IPX, SPX, and AppleTalk, most routers in China run TCP/IP protocols. A router is usually connected to two or more logical ports identified by IP subnet or Point-to-Point Protocol, and has at least one physical port. The router technology determines the output port and Next Hop address based on the network layer address in the received data packet and the route table maintained inside the router, and overwrites the data packet header at the link layer to forward data packets. The router dynamically maintains the route table to reflect the current network topology, and maintains the route table by exchanging routing and link information with other routers on the network.

Vro category

Currently, vro classification methods vary. Different classification methods are associated, but not completely consistent. In terms of structure, a router can be divided into a modular structure and a non-modular structure. Generally, a high-end router is a modular structure, and a low-end router is a non-modular structure.

Vrouters can be divided into core routers and access routers according to their network locations. The core router technology is located in the network center. It usually uses high-end routers and requires Fast Packet exchange capability and high-speed network interfaces. Generally, it is in a modular structure. The Access Router is located at the edge of the network and usually uses low-end routers, relatively low-speed ports and strong access control capabilities are required.

In terms of functions, the router technology can be divided into general-purpose routers and dedicated routers. Generally speaking, the router technology is a general-purpose router. A dedicated router is usually used to optimize router interfaces and hardware for a specific function. For example, the Access Router is used as a dial-up user to enhance the PSTN interface and signaling capabilities; VPN routers enhance tunnel processing capabilities and hardware encryption. broadband access routers emphasize the number and type of broadband interfaces. In terms of performance, the router technology can be divided into line rate routers and non-line rate routers. Generally, a wire speed router is a high-end router that can forward data packets at the Media rate. The middle and low-end routers are non-wire speed routers, but some new broadband access routers are also capable of wire speed forwarding.

In the formulation of standards, the router technology can be divided into two categories: high-end routers and low-end routers. The backplane exchange capability is greater than 20 Gbit/s, A router with a packet switching capability greater than 20 Mbit/s is called a high-end router. A router with a packet switching capability less than 1 Mbit/s is called a low-end router. Take the Cisco company with the largest market share as an example. The 12000 series are high-end routers, and The 7500 or lower series routers are low-end routers. Obviously, there is a gap in the above Division: vrouters with 1 Mbit/s or more and 20 Mbit/s or less have no reference standards. According to the standard series, there should be mid-range router specifications. However, because the mid-range router technology is not special, you can refer to the low-end router or high-end router, so there is no separate standard.